The present invention relates to constant gas or fluid flow regulators and more particularly to a flow regulator having a spring biased piston connected to a pin valve and being capable of maintaining a constant gas or fluid flow rate in both high pressure, low volume and low pressure, high volume environments with changes in inlet or outlet pressure. The present invention also accommodates high pressure, high volume and low pressure, low volume systems.
Constant gas or fluid flow regulators capable of accommodating low pressure, high volume fluid flow often employ sliding sleeves for opening and closing parts of the regulators. Also, multiple poppet type valves may be used for low pressure, high volume fluid flow regulation. The above prior art, however, generally cannot accommodate high pressure, low volume gas or fluid flow.
This invention, on the other hand, is able to provide constant gas or fluid flow in high or low pressure and high or low volume ranges due to the low numerical value of the ratio of the surface area of the pin valve stem to the surface area of the piston within the flow controller valve.
The present invention is also different from the above sliding sleeve and multiple poppet type valves in that the piston of the valves of the prior art move relative to the valve body to vary fluid flow as the pressure changes, while the piston of applicant's invention does not move substantially relative to the valve body after fluid flow has stabilized. Instead, constant spring force on the piston in the present invention allows constant flow with changing pressure. The present invention thus experiences less wear and tear from moving parts.
Constant fluid flow regulators taught in prior art regulate fluid flow by adjustment screws that directly vary spring tension by attachment to the piston spring itself. Other regulators change fluid flow by altering piston position via springs and ball bearings located over the piston. The system employing springs and ball bearings is subject to extreme torque due to the fluid pressure in the chamber.
The present invention, on the other hand, varies gas or fluid flow by adjustment of the valve seat position, which in turn adjusts piston spring tension. The change in spring tension thus varies the pressure differential across the piston. Torque associated with chamber fluid pressure is thus reduced.
Finally, other constant fluid flow regulators allow fluid flow around the piston periphery to constitute the principal channel of fluid passage through the regulator. In the high pressure, low flow embodiment of the present invention, the sole flow passage is a single orifice or group of orifices through the piston. This calibrated flow orifice, or orifices, allows precise measurement and calculation of prospective flow rates, unavailable in most of the prior art devices. The use of the sole flow path in one of the applicant's embodiments allows the valve to function at high pressure, unlike the prior art. Fluid flow around the piston periphery in the prior art prevents use in high pressure, low fluid environment.